{"Entry":{"collection":"protocol","key":"negotiateprotocolversion-b","name":"NegotiateProtocolVersion","aliases":["NegotiateProtocolVersion","Byte1('v')"],"metadata":{"aliases":["NegotiateProtocolVersion","Byte1('v')"],"category":"Backend messages","content_hash":"a8f053909db5a27dae5755005b0f0ebd9fdf2bf3f1aa4efacb980f706677da4d","derived_content_hash":"02863543f56478714732028684b9fd5c1fcf1d23ce7769388a454405e55ccd6a","imported_at":"2026-09-30T00:40:44.47683+08:00","name":"NegotiateProtocolVersion","name_zh":"","slug":"negotiateprotocolversion-b","summary":"NegotiateProtocolVersion is a backend protocol message. Identifies the message as a protocol version negotiation message."}},"Definition":{"Collection":"protocol","Key":"negotiateprotocolversion-b","SourceDatabase":"center","Version":"18","SourceTable":"protocol_message","SourceKey":"negotiateprotocolversion-b","SourceRevision":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f","Facts":{"comparison_data":{"direction":"B","fields":[{"description":"Identifies the message as a protocol version negotiation message.","format":"Byte1('v')"},{"description":"Length of message contents in bytes, including self.","format":"Int32"},{"description":"Newest minor protocol version supported by the server for the major protocol version requested by the client.","format":"Int32"},{"description":"Number of protocol options not recognized by the server.","format":"Int32"},{"description":"The option name.","format":"String"}]},"comparison_hash":"e1b8b535cfb24c3820d56a4669f869a4b863ed8bb22fa5147c2e8e69a7deb2ba","description":["NegotiateProtocolVersion is a backend protocol message. Identifies the message as a protocol version negotiation message."],"description_zh":"Byte1('v') 标识消息为协议版本协商消息。 Int32 消息内容的长度（以字节为单位），包括其自身。 Int32 对于客户端请求的协议主版本，服务器所支持的最新协议次版本。 Int32 服务器无法识别的协议选项数量。 接下来，对于服务器无法识别的每个协议选项，都有以下内容： String 选项名称。","description_zh_html":"\u003cp\u003e协议消息 NegotiateProtocolVersion (B)。\u003c/p\u003e\u003ch3\u003e同版本中文手册定义\u003c/h3\u003e\u003cdd\u003e\u003cdiv class=\"variablelist\"\u003e\u003cdl class=\"variablelist\"\u003e\u003cdt\u003e\u003cspan class=\"term\"\u003eByte1('v')\u003c/span\u003e \u003c/dt\u003e\u003cdd\u003e\u003cp\u003e\n         标识消息为协议版本协商消息。\n        \u003c/p\u003e\u003c/dd\u003e\u003cdt\u003e\u003cspan class=\"term\"\u003eInt32\u003c/span\u003e \u003c/dt\u003e\u003cdd\u003e\u003cp\u003e\n         消息内容的长度（以字节为单位），包括其自身。\n        \u003c/p\u003e\u003c/dd\u003e\u003cdt\u003e\u003cspan class=\"term\"\u003eInt32\u003c/span\u003e \u003c/dt\u003e\u003cdd\u003e\u003cp\u003e\n         对于客户端请求的协议主版本，服务器所支持的最新协议次版本。\n        \u003c/p\u003e\u003c/dd\u003e\u003cdt\u003e\u003cspan class=\"term\"\u003eInt32\u003c/span\u003e \u003c/dt\u003e\u003cdd\u003e\u003cp\u003e\n         服务器无法识别的协议选项数量。\n        \u003c/p\u003e\u003c/dd\u003e\u003c/dl\u003e\u003c/div\u003e\u003cp\u003e\n      接下来，对于服务器无法识别的每个协议选项，都有以下内容：\n     \u003c/p\u003e\u003cdiv class=\"variablelist\"\u003e\u003cdl class=\"variablelist\"\u003e\u003cdt\u003e\u003cspan class=\"term\"\u003eString\u003c/span\u003e \u003c/dt\u003e\u003cdd\u003e\u003cp\u003e\n         选项名称。\n        \u003c/p\u003e\u003c/dd\u003e\u003c/dl\u003e\u003c/div\u003e\u003c/dd\u003e\u003cp\u003e\u003ca href=\"/zh/docs/18/protocol-message-formats.html#PROTOCOL-MESSAGE-FORMATS-NEGOTIATEPROTOCOLVERSION\"\u003e查看完整中文手册与上下文\u003c/a\u003e。\u003c/p\u003e","direction":"B","facts":[{"label":"Direction","value":"Backend → frontend"},{"label":"First wire field","value":"Byte1('v')"},{"label":"Field entries","value":"5"},{"label":"Documented flow contexts","value":"Start-up"}],"facts_zh":[{"label":"方向","value":"后端 → 前端"},{"label":"首个线上协议字段","value":"Byte1('v')"},{"label":"字段条目","value":"5"},{"label":"手册中的交互阶段","value":"启动"}],"fields":[{"description":"Identifies the message as a protocol version negotiation message.","format":"Byte1('v')"},{"description":"Length of message contents in bytes, including self.","format":"Int32"},{"description":"Newest minor protocol version supported by the server for the major protocol version requested by the client.","format":"Int32"},{"description":"Number of protocol options not recognized by the server.","format":"Int32"},{"description":"The option name.","format":"String"}],"manual_html":"\u003cdl\u003e\u003cdd\u003e\n\u003cdiv class=\"variablelist\"\u003e\n\u003cdl class=\"variablelist\"\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eByte1('v')\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eIdentifies the message as a protocol version negotiation message.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eInt32\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eLength of message contents in bytes, including self.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eInt32\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eNewest minor protocol version supported by the server for the major protocol version requested by the client.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eInt32\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eNumber of protocol options not recognized by the server.\u003c/p\u003e\n\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003cp\u003eThen, for protocol option not recognized by the server, there is the following:\u003c/p\u003e\n\u003cdiv class=\"variablelist\"\u003e\n\u003cdl class=\"variablelist\"\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eString\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eThe option name.\u003c/p\u003e\n\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003c/dd\u003e\u003c/dl\u003e","manual_path":"/docs/18/protocol-message-formats.html","related":[{"label":"Protocol flow and exchange examples","url":"/docs/18/protocol-flow.html"},{"label":"Protocol overview","url":"/docs/18/protocol-overview.html"},{"label":"Start-up","url":"/docs/18/protocol-flow.html#PROTOCOL-FLOW-START-UP"}],"release":{"channel":"stable","label":"18.6","major":"18","ref":"https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2","revision":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"},"sections":[{"paragraphs":["The complete definition below retains repetition, counts and conditional fields. A numbered table row is a documented field definition, not a fixed byte offset. Integer encodings and flow rules follow the same-version protocol chapter."],"title":"Framing and repetition"}],"sections_zh":[{"paragraphs":["下方完整定义保留重复项、计数与条件字段。表格行号表示文档中的字段定义，并非固定字节偏移量。整数编码与交互流程以同版本协议章节为准。"],"title":"消息边界与重复字段"}],"signature":"NegotiateProtocolVersion (B)","sources":[{"label":"PostgreSQL 18 English manual","path":"protocol-message-formats.html","sha256":"53f37652ac2c089e30ada87d8aee7bdd0f26695b03f275302e526a807d2a1f23","url":"/docs/18/protocol-message-formats.html#PROTOCOL-MESSAGE-FORMATS-NEGOTIATEPROTOCOLVERSION"}],"tables":[{"columns":[{"key":"c0","label":"Position"},{"key":"c1","label":"Format"},{"key":"c2","label":"Meaning"}],"key":"fields","rows":[{"c0":"1","c1":"Byte1('v')","c2":"Identifies the message as a protocol version negotiation message."},{"c0":"2","c1":"Int32","c2":"Length of message contents in bytes, including self."},{"c0":"3","c1":"Int32","c2":"Newest minor protocol version supported by the server for the major protocol version requested by the client."},{"c0":"4","c1":"Int32","c2":"Number of protocol options not recognized by the server."},{"c0":"5","c1":"String","c2":"The option name."}],"title":"Wire fields in documented order"}],"tables_zh":[{"columns":[{"key":"c0","label":"位置"},{"key":"c1","label":"格式"},{"key":"c2","label":"含义"}],"key":"fields","rows":[{"c0":"1","c1":"Byte1('v')","c2":"标识消息为协议版本协商消息。"},{"c0":"2","c1":"Int32","c2":"消息内容的长度（以字节为单位），包括其自身。"},{"c0":"3","c1":"Int32","c2":"对于客户端请求的协议主版本，服务器所支持的最新协议次版本。"},{"c0":"4","c1":"Int32","c2":"服务器无法识别的协议选项数量。"},{"c0":"5","c1":"字符串","c2":"选项名称。"}],"title":"按手册顺序排列的线上协议字段"}],"zh_from":{"authored_translation":"source-derived-identity","body_sha256":"96304b81de088e088f71f75955909fda44bcc38f36dfc2f6754de1312921db3e","kind":"same-version-chinese-manual-with-source-derived-identity","manual":{"anchor":"PROTOCOL-MESSAGE-FORMATS-NEGOTIATEPROTOCOLVERSION","build_id":107,"extraction":"exact-definition","fragment_sha256":"4821dcd2d40a4110518fcba142346825be4594459116c491085d58da1b17fe1a","locale":"zh-Hans","page_key":"protocol-message-formats.html","source_hash":"0be0a37b38d80c96c157ca9fcfe9222995654664aad8136f7ac2b1b552f6753a","source_revision":"unknown:rendered-translation-baseline","translated_from_revision":null,"translation_revision":"git:b1b500221dbe5437cfca004d6b04d3f6e422765d;html-sha256:08e987a66af27b98444a8057c256314eafa13611a3fb9e888214fc436824244b","url":"/zh/docs/18/protocol-message-formats.html#PROTOCOL-MESSAGE-FORMATS-NEGOTIATEPROTOCOLVERSION","version":"18"},"runtime_rerun":false,"source_facts_revision":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}},"ManualEvidence":{"manual_path":"/docs/18/protocol-message-formats.html","release":{"channel":"stable","label":"18.6","major":"18","ref":"https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2","revision":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"},"sources":[{"label":"PostgreSQL 18 English manual","path":"protocol-message-formats.html","sha256":"53f37652ac2c089e30ada87d8aee7bdd0f26695b03f275302e526a807d2a1f23","url":"/docs/18/protocol-message-formats.html#PROTOCOL-MESSAGE-FORMATS-NEGOTIATEPROTOCOLVERSION"}]},"MeasuredEvidence":{}},"Text":{"Collection":"protocol","Key":"negotiateprotocolversion-b","SourceDatabase":"center","Version":"18","Locale":"en","Title":"NegotiateProtocolVersion","Summary":"NegotiateProtocolVersion is a backend protocol message. Identifies the message as a protocol version negotiation message.","BodyHTML":"\u003cdl\u003e\u003cdd\u003e\n\u003cdiv\u003e\n\u003cdl\u003e\n\u003cdt\u003e\u003cspan\u003eByte1(\u0026#39;v\u0026#39;)\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eIdentifies the message as a protocol version negotiation message.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan\u003eInt32\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eLength of message contents in bytes, including self.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan\u003eInt32\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eNewest minor protocol version supported by the server for the major protocol version requested by the client.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan\u003eInt32\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eNumber of protocol options not recognized by the server.\u003c/p\u003e\n\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003cp\u003eThen, for protocol option not recognized by the server, there is the following:\u003c/p\u003e\n\u003cdiv\u003e\n\u003cdl\u003e\n\u003cdt\u003e\u003cspan\u003eString\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eThe option name.\u003c/p\u003e\n\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003c/dd\u003e\u003c/dl\u003e","SourceRevision":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f","ContentHash":"59707438c9b4b93510351e7e339c82d3b5fee1fbc49cacd1619ab7a980108a49","Payload":{"description":["NegotiateProtocolVersion is a backend protocol message. Identifies the message as a protocol version negotiation message."],"manual_html":"\u003cdl\u003e\u003cdd\u003e\n\u003cdiv class=\"variablelist\"\u003e\n\u003cdl class=\"variablelist\"\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eByte1('v')\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eIdentifies the message as a protocol version negotiation message.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eInt32\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eLength of message contents in bytes, including self.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eInt32\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eNewest minor protocol version supported by the server for the major protocol version requested by the client.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eInt32\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eNumber of protocol options not recognized by the server.\u003c/p\u003e\n\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003cp\u003eThen, for protocol option not recognized by the server, there is the following:\u003c/p\u003e\n\u003cdiv class=\"variablelist\"\u003e\n\u003cdl class=\"variablelist\"\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eString\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eThe option name.\u003c/p\u003e\n\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003c/dd\u003e\u003c/dl\u003e","related":[{"label":"Protocol flow and exchange examples","url":"/docs/18/protocol-flow.html"},{"label":"Protocol overview","url":"/docs/18/protocol-overview.html"},{"label":"Start-up","url":"/docs/18/protocol-flow.html#PROTOCOL-FLOW-START-UP"}],"sections":[{"paragraphs":["The complete definition below retains repetition, counts and conditional fields. A numbered table row is a documented field definition, not a fixed byte offset. Integer encodings and flow rules follow the same-version protocol chapter."],"title":"Framing and repetition"}],"tables":[{"columns":[{"key":"c0","label":"Position"},{"key":"c1","label":"Format"},{"key":"c2","label":"Meaning"}],"key":"fields","rows":[{"c0":"1","c1":"Byte1('v')","c2":"Identifies the message as a protocol version negotiation message."},{"c0":"2","c1":"Int32","c2":"Length of message contents in bytes, including self."},{"c0":"3","c1":"Int32","c2":"Newest minor protocol version supported by the server for the major protocol version requested by the client."},{"c0":"4","c1":"Int32","c2":"Number of protocol options not recognized by the server."},{"c0":"5","c1":"String","c2":"The option name."}],"title":"Wire fields in documented order"}]}},"RequestedLocale":"en","Fallback":false,"Versions":["10","11","12","13","14","15","16","17","18","19","20"],"Locales":["en","zh-Hans"],"Signatures":null,"Spellings":null,"SQLState":null,"Evidence":null}